"If it carries on like this other clubs -- not so well structured as us -- will make losses," he added.

"Of course, you could insist nobody earns more than €5m, but you cannot win the Champions League like that. [Lionel] Messi earns €5m a month."

The 1974 World Cup winner World Cup winner spoke about Bayern's progress to becoming a footballing superpower, recalling: "When I first I became general manager in 1979, aged 27, we had turnover of 12m Deutschmarks and debts of 7m.

"But we have always tried to deliver sporting success on the back of sound business practice. Now we generate turnover of €650m.

"There's turnover of €110m on shirts and fan merchandising alone. Compare that to 1979 when we only used to send out a few scarves, hats and postcards from our mailroom."